Organic silicon / nano-silica composite oil-blocking and water-blocking type coated proppant and preparation method thereof

By forming a three-dimensional interpenetrating network structure of organosilicon/nano-SiO2 composite oil-permeable and water-blocking proppant on the surface of aggregates, the problem of insufficient water-blocking performance of existing proppants in deep wells is solved, achieving high efficiency in oil permeability and water blocking as well as pressure resistance, thus meeting the needs of deep oil and gas reservoir development.

CN122168267APending Publication Date: 2026-06-09XINMI WANLI IND DEV
View PDF 3 Cites 0 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
XINMI WANLI IND DEV
Filing Date
2026-03-31
Publication Date
2026-06-09

AI Technical Summary

Technical Problem

Existing oil-permeable and water-blocking proppants are insufficient to meet higher water-blocking performance requirements under harsh conditions such as deep layers and high temperatures. The hydrophobic properties of polyurethane resin in existing double-layer coating structures are limited, making it difficult to meet higher water-blocking requirements.

Method used

A method for preparing an organosilicon/nano-SiO2 composite oil-permeable and water-resistant coating proppant is adopted. By forming a continuous and dense three-dimensional interpenetrating network structure on the surface of aggregate, utilizing Si-O-Si covalent bonds and polymer chain physical entanglement, combined with the hydrophobic properties of hydrophobic nano-SiO2, a stable coating layer is formed. Stepwise temperature increase curing avoids bubbles and pinhole defects, thereby improving the density and compressive strength of the coating layer.

Benefits of technology

It achieves excellent oil permeability and water resistance performance and compressive strength under high temperature and high pressure conditions in deep wells, while also exhibiting long-term stability. This reduces production costs and adapts to harsh downhole conditions, meeting the exploitation needs of deep oil and gas reservoirs.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure SMS_1
    Figure SMS_1
  • Figure SMS_2
    Figure SMS_2
Patent Text Reader

Abstract

This invention discloses an organosilicon / nano-SiO2 composite oil-permeable and water-blocking film support agent and its preparation method. The preparation method provided by this invention uses 20-40 mesh ceramsite as aggregate. After activation with a silane coupling agent, a sol-gel method is used to uniformly coat a silicone resin prepolymer sol prepared from methyltrimethoxysilane, dimethyldimethoxysilane, and hydrophobic nano-SiO2. The coating is then cured by stepped temperature increase to obtain the organosilicon / nano-SiO2 composite oil-permeable and water-blocking film support agent. This proppant exhibits good oil permeability and water resistance, with oil-water ratios of 2.80~2.98, 2.52~2.84, and 2.24~2.61 at pressures of 52MPa, 69MPa, and 86MPa, respectively, which are superior to pure organosilicon and traditional polyurethane-coated proppants. It also boasts high compressive strength, with breakage rates of only 6.5~7.0% and 8.0~8.5% at pressures of 52MPa, 69MPa, and 86MPa, respectively, meeting the requirements for deep well fracturing. Furthermore, it demonstrates good long-term stability, with a performance degradation rate of only 2.0~3.0% after immersion in a 2% KCl solution at 90℃ for 30 days.
Need to check novelty before this filing date? Find Prior Art

Claims

1. A method for preparing an organosilicon / nano-SiO2 composite oil-permeable and water-blocking film support, characterized in that, Includes the following steps: S1. Activate the aggregate and prepare a silicone resin prepolymer sol containing nanoparticles; The aggregates include quartz sand or ceramsite; S2. Cool the activated aggregate to 60~100℃, spray the silicone resin prepolymer sol containing nanoparticles onto the aggregate surface, and keep it at the temperature for 1~4 hours to obtain the coated proppant. S3. The coated support is cured by step heating to obtain an organosilicon / nano-SiO2 composite oil-permeable and water-blocking coated support.

2. The preparation method of the organosilicon / nano-SiO2 composite oil-permeable and water-resistant coating support agent according to claim 1, characterized in that, Specific methods for activating aggregates include: Aggregates with a particle size of 20-40 mesh are heated to 150-250°C, and a silane coupling agent solution is added. After stirring and reacting, activated aggregates are obtained.

3. The preparation method of the organosilicon / nano-SiO2 composite oil-permeable and water-resistant coating support agent according to claim 1, characterized in that, Specific methods for preparing silicone resin prepolymer sol containing nanoparticles include: After mixing organosilicon monomers, solvents, and hydrophobic nano-SiO2, the mixture is dispersed by ultrasound or high shear, deionized water is added with stirring, and the pH value is adjusted to 7.5~9 with an alkaline catalyst. The mixture is then stirred and hydrolyzed at 30~60℃ for 0.5~2h to obtain a silicone resin prepolymer sol containing nanoparticles.

4. The preparation method of the organosilicon / nano-SiO2 composite oil-permeable and water-resistant coating support agent according to claim 3, characterized in that, The organosilicon monomer is at least one of methyltrimethoxysilane, dimethyldimethoxysilane, and methyltriethoxysilane.

5. The preparation method of the organosilicon / nano-SiO2 composite oil-permeable and water-resistant coating support agent according to claim 3, characterized in that, The solvent is at least one of ethanol and isopropanol.

6. The preparation method of the organosilicon / nano-SiO2 composite oil-permeable and water-resistant coating support agent according to claim 3, characterized in that, The alkaline catalyst is sodium hydroxide solution, ammonia, or triethylamine.

7. The preparation method of the organosilicon / nano-SiO2 composite oil-permeable and water-resistant coating support agent according to claim 3, characterized in that, The hydrophobic nano-SiO2 has a particle size of 10~50nm and a specific surface area ≥200m². 2 / g.

8. The preparation method of the organosilicon / nano-SiO2 composite oil-permeable and water-resistant coating support agent according to claim 3, characterized in that, Specific methods for curing the coated support agent by stepwise temperature increase include: The coated support is cured at 80~100℃ for 1~2 hours; then cured at 120~150℃ for 1~2 hours.

9. A silicone / nano-SiO2 composite oil-permeable and water-resistant coating support agent, characterized in that, It is prepared by the method of any one of claims 3 to 8 for the preparation of organosilicon / nano-SiO2 composite oil-permeable and water-resistant coating support.

10. The organosilicon / nano-SiO2 composite oil-permeable and water-resistant coating support agent as described in claim 9, characterized in that, The organosilicon / nano-SiO2 composite oil-permeable and water-resistant coated support agent includes aggregate and a coating layer covering the surface of the aggregate. The coating layer is formed by in-situ polymerization of the organosilicon resin formed by the hydrolysis and condensation of the organosilicon monomer under alkaline conditions and the hydrophobic nano-SiO2. The coating layer has a continuous and dense three-dimensional interpenetrating network structure. The three-dimensional interpenetrating network structure is formed by the interpenetration of organosilicon resin and hydrophobic nano-SiO2 through Si-O-Si covalent bonds and / or physical entanglement of polymer chains.